The present invention relates to a hydraulic system for actuating a clutch and/or a variable speed drive unit of a belt-driven conical-pulley transmission of a vehicle with a variable transmission ratio, in particular a commercial vehicle, and having at least one hydraulic energy source. In a preferred exemplary embodiment, the hydraulic system includes a torque sensor. However, the invention also includes exemplary embodiments without torque sensors.
An object of the invention is to provide a hydraulic system which enables greater efficiency or reduction in the size of the hydraulic energy source. In particular, the supplying of various components is to be improved.